Rubbing device



Feb. 3, 1942. o. A.I KEHLE j 2,272,008 RUBBING DEVICE Filed oct. 24, 193s ww; I.' an

. o llzvenlor.

section; and

` Products` Company strains.

. My invention. haslito'do witlifimprovemnts in l rubbingr machines such, for instance, as 'areused in sanding or bufflngoperations. 1 yIn rparticularyit is yan .object of myinvention to provide a machinefof :this characterhaving a propelling unitand abuflinggpadeleme'nt and in which the Apropelling unit is `housed 'within the padelement. o Another object is `to providenovel; .ecient and durable means for connecting thelworking face of the pad to the remaining elements.

Another object is character wherein and mounted as to reduce to a minimum the amount of vibration transmitted to the yhand. of the operator. y i

Another object is to provide'` in suchv a device a construction whichis extremely quiet inoperation.

, Another object is to providea rubbing device to provide a device of this the parts are so assembled Patented Feb. 3, 1942 a Y y at each" of its sides'.

` hofclaimis here nade to hasa' downwardly! depending skirt :portion ,5a Extending longitudinally in and adjacent'oney sidegof'- pad 5 there is aree'- tangularr'ece'ss l0 rinvfwhich'is mounted the valve operating lever-5to be later described.

f Ai motorli5 of any suitable constructiony isrsecuredtofand suspended fromlplate 6 by means of screws I6 which passthrough'holes 8 and. 9 and arel threaded at their lowerv ends into holes in'thetop' ofthe motor as. shown, the sides of the'm'otorbeing-covered by flanges 6a.. While the particular construc- `tionf'o'fth'efmotor-element per se,'I find that a uid no'tor` of the type' generally described in my copend'ing application Seria-lv Number 280,118, filed J uneZO, 1939, is well suited forr the ypurpose andv ,inasi'n'ucl'i asV referericemay beimadev to that i' @pending-applicationfor`ldetails of Ithe working in'which the rubbing pad is so connected to the propelling rocation of the `workingelement 'inra .re1ative1y constant plane.v '-1 Y Another object is :to'provid a device 'which isi" element as to provide a smooth recipextremely durable, easy toassemble and disasfrom the hereinafter containedfdetailed descrip,-

tion when considered in connection with the ac'- 'parts of the motor element,1it will sufficev here tostate lthat, it includesl a `block 15a having Aa lor'igitudin'all bore andv piston (not shown) and extending yvertically through the center of' the piston memberlthere is apowei transmitting pin ll'whichiis' reciprocated bythe piston andwhich projects at lits'top endithrough the motor `valve operatin'gyoke 20 'and 4carries .a nut'2l at itstop` end.1lYoke'20 i'sffulcru'med on/al pin 22,r carried resultant advantagesthereof, and the particular companylng drawing forming a part'hereof and illustrating one embodiment `o`f the `invention. -In the drawing: y Figlisaplanview; f Fig. 2 is a longitudinal section .online 2`-2}of Fig. 1, with someparts being shown in elevation;

Fig. 3 is an end View taken 'on lline' 3'-3 of Fig. k2, with some parts being shown 'in cross- W to the drawing, AIgshow top resilient pad 5, preferably composed of. rubber,`

faced at its underside by a vmetal`1i late6fwhich has downwardly extending side flanges 6a,"`wh`ich metal plate is upwardlybowedat r ,its center `,6b o

to provide space for thereciprocating element to be later described. A plurality of holes '8 (preferably four in number) l'extend vertically through Kb pad 5, and concentric'with there isA a hole 9 of relatively small through plate 6. As

each of-v. said holes diameter bythe'fmotorl block l5a-and acts as a lever to engage. andactuatelthei'valve pin 25 controlling the inletpand'ioutlet of yfluidto 'and from the respective ends ofv the an elongatedfopenings26'provide'dthrough the't'op'of the motor elongated opening 21"alsoprovided throughfthe `topv ofthe.' motor block. An` air inlet r30' to the 29'in one of Vthe side flanges motor is provided through the side fof 'the motor block; said inlet being? accessible through an open- 6o and being .controlled by a valve 3| :(Fi'g. 3) vwhich is adapted tobel movedoff 'its seat Y32 Kby stem 33,'said inlet @Stem '3'3 -is'in turn manually actuated into rvalve fiopening positionby the valvelever 34 which is 535: 'coil spring vIfagainstfiplug"3T/threaded into the'. motor block, a jand :atv itsitop against valve 3|, urges the 'valve fipivotallyconnect'e'd toijpad' plate 5v by pivot lpin 36, 'which' seats at its Ibottom n the topof the motor block and -1plate;6,` I provide'a pair of rubber shock absorbers 38 disposed one at eachend of the'elon "gated opening "26 in position to V.be contacted by best shown in Fig; 3, pad-5 55 ',.\."A"p'ar 'ofoppo'sitely disposed, relatively thick l piston. The vtop'endioi. thepinzlfl reciprocates along tionary. The arched ilexible and transverse clamping strips 45, said strips being downwardly bent at their ends as shown at 4l to resist lateral displacement of the webs` A shoe 50 is secured to the plate 44 by means of rivets 53 passing through holes in its flanged portions 54, and into this shoe fits the enlarged end Ila of pin I'T, one side of the shoe being open, as shown at l, to pass the enlarged endA lla during assembling and disassembling. The lower pin end Ila is normally spaced from the bottom of the shoe to permit vertical movement of the pin end lla Within the shoe as the webs 40 are exed. The top of the shoe has an inwardly extending flange portion 55 which overhangs the enlarged pin end Ha to prevent further upward movement of the pin with respect to the shoe after it reaches the uppermost position shown in Fig. 2.

A ilexible cushion 60 is secured to plate 44 by having its socketed endsl 5I fit over the respective ends of plate 44. Cushion 60 is preferably composed of rubber and has a dove-tailed recess 63 at its bottom into which is moulded a resilient pad 65 which is preferably of felt or the like. An abrasive or working .sheet 'I0 is stretched over the bottom face of cushion B9 and pad 6'5, the respective ends of said sheet 'It being folded around the overhanging ends 60u and conned by being held against plate 44 by the overhanging ends 60a of cushion 60, the loose end of the working sheet tting into recesses `6'! provided in the top face of cushion 60.

In operation, the longitudinal movement of the piston within the bore reciprocates its carried pin Il which in turn transmits the reciprocating movement to the working face of the pad element while the operator holds the top plates 5 and 6 and the carried motor relatively stawebs 40 permit the rubbing pad element to be reciprocated without tending to raise the ends of the pad at and adjacent the ends of the stroke, thus maintaining the movement of the pad in a substantially constant plane, although, due to the flexibility of the working face of the pad itself, it is capable 4 of flexing to follow a curved or uneven surface being worked upon.

In devices of the prior art, the motor is usually the topmost element, the pad being secured to or carried by the bottom of the motor. In such cases, if the top ends of the webs are firmly secured to the bottom of the motor, the webs are so relatively short that it requires considerable exertion on the part of the operator to hold the motor stationary and the short webs deteriorate rapidly due to the great stresses placed upon them by reciprocation of the working face of the pad. My invention has a distinct advantage over such devices inasmuch as in my device, wherein the pad element may be said to consist of the I webs 4U and the rubbing element, the webs may be of substantially greater length and may be thicker and more durable. The flexing stress on any part of the webs is not very great, so that the top portion may be held stationary with little effort and the webs are capable of long life, the operation being at the same time much smoother. Furthermore, since the thickness of the rubber webs is interposed between the top of the motor and the top plates, the vibration transmitted to the hand of the operator is reduced to a minimum and the motor noises are materially damped because the motor is substantially housed within a rubber casing provided by the pad element.

While, in the foregoing description, I have resorted to various details of structure and association of parts, I wish it understood that I do not thereby conne ymy invention to such specific details. Rather, various modilcations and adaptations may be made within the broader scope of the invention as defined by the appended claims.

Iclaim:

1. A device of the class described comprising a rubbing element, a pair of flexible strips secured -at their lower ends to the respective ends of the rubbing element and extending upwardly therefrom, a top plate, a motor secured to and suspended below said plate, the top ends of said flexible strips being secured between the motor and said plate, side flanges on said plate extending downwardly to cover the sides of the motor and means operatively connecting the motor to the rubbing element whereby to oscillate the latter. l

2. The device of claim 1 which includes a resilient member mounted on said top plate and extending downwardly along the exterior surface of said side flanges of the top plate to provide a gripping surface.

3. A rubbing device including a pad element comprised of top and bottom portions spaced apart by flexible end walls, a motor secured to and suspended below the top portion, a power transmitting pin adapted to be oscillated by the motor and projecting therebelow to oscillate the bottom portion of the pad element with respect to the motor, and a shoe secured to the bottom portion and opening upwardly to receive the lower end of said pin, the bottom end of said pin being normally spaced from the bottom of the shoe whereby to permit of vertical movement of the bottom portion of the pad element with respect to the top portion upon ilexing of the end walls.

4. A rubbing device including a pad element comprised of top and bottom portions spaced apart by flexible end walls, a motor suspended below the top portion between said end walls, a power transmitting pin operatively connected at its top end to the motor and projecting downwardly therefrom, the lower end of said pin being headed, and a shoe secured to said bottom portion of the pad element and opening upwardly to receive said headed end of the pin, said shoe having an inwardly projecting top flange overhanging the headed end ofthe pin and a slotted side wall through which said headed end of the lpin may be laterally inserted into and removed from the shoe.

5. A rubbing device including a pad element comprised of top and bottom portions spaced apart by flexible end walls, a motor secured to and suspended below the top portion, said motor having a reciprocating valve actuating pin projecting through an elongated slot in its top wall, resilient `bumper members positioned between the top Aportion of the pad and the top of the motor and positioned one at each end vvof said slot wherebyf tok bevcontactedfby said. l, pin at the respective extremes ofits movement along said slot, and means operatively connecting the motor to the lowerportion of the pad whereby to move the latter with'respect to the f motor. Y f Y 6. A rubbing device` including a pad element comprised of top and bottom .portions spaced apart by flexible end Walls, said top portion being adapted to be held stationary with respect to the bottom portionl the top portionfof said.; I

' of said end walls the sai'drigid bott rn plate `vsrh'ereby to lbe posi'- A toned between saidend Walls, the upper ends vbeing]confined betweenA the fmotor and said bottomj-icilate; and means operl j atively connecting themotor to the bottom-pors "tion of 'theffpaldxjyelement whereby fjOimove the v latter withv respect `to (the top-portion. 

